1. Field of the Invention
This invention relates generally to adjustable wrenches, and more particularly to a locking ratchet wrench which has a stationary jaw and a movable jaw which will automatically fit a variety of nut or bolt sizes and have the recommended wrench clearance on each size and will ratchet in either direction and turn a bolt or nut in either direction without removing the wrench after each turn.
2. Brief Description of the Prior Art
Heretofore, numerous tools including adjustable wrenches, pliers, and vise grips have been designed to fit a variety of bolt sizes by turning a screw or squeezing a handle.
One of the major problems with pliers type devices is that they do not have jaws which contact the bolt parallel to each other at all times. Pliers also require a strong grip.
Adjustable wrenches have to be adjusted to each size of bolt by turning a screw, then moving the hand to the wrench handle to turn the bolt. They also have to be removed from the bolt and replaced on the bolt for the next turn. The adjustable wrenches often lose their adjustment after several turns and require frequent readjustment. The loss of adjustment also increases the risk of the wrench jumping over the corners of the bolt, thus damaging the bolt and increases the risk of injury to the user. When the prior art adjustable wrenches are adjusted, it is difficult to set it to the recommended wrench clearance. If the clearance is too tight it is difficult to remove and replace it on the bolt. The prior art adjustable wrenches must also be readjusted each time the user goes to a different size bolt.
There are several patents which disclose various adjustable wrenches.
Hersey, U.S. Pat. No. 419,854and Cox, U.S. Pat. No. 4,580,468 discloses non-ratcheting adjustable pipe wrenches having a sliding jaw and a pivoting jaw and a sliding jaw and a stationary jaw respectively. The wrench jaws do not have parallel faces and would not be suitable for use on nuts or bolts.
Upson, U.S. Pat. No. 1,206,947 discloses a wrench which must be removed and replaced on the bolt after each turn and is not capable of ratcheting in either direction relative to the bolt to turn the bolt in either direction without removing the wrench.
Feiring, U.S. Pat. No. 2,573,421 discloses a cam actuated pivoted jaw wrench which requires removal and replacement of the head member to use the wrench on different size and shapes of nuts or bolts.
Cutter, U.S. Pat. No. 3,379,079 discloses a clamping and locking wrench having first and second actuating arms rotatably connected together at one end, a rotatable member connected to the arms to open and close the jaws, and a toggle joint locking mechanism connected to the rotatable member to lock the arms in position.
The present invention is distinguished over the prior art in general, and these patients in particular by a locking ratchet wrench which has a main body with an elongate handle portion and a stationary jaw at one end. A movable jaw with ratchet teeth at its rear end is slidably fitted on the main body. A locking pawl block has teeth at the forward end thereof corresponding to the movable jaw ratchet teeth and movable into and out of engagement therewith. A movable handle is pivotally mounted on the main body and connected to the locking pawl block to move it into and out of toothed engagement with the movable jaw.